In the present article, I will try to elucidate how relying on the goal concept facilitates the development and testing of theories in the science of motivation. For this purpose, I will focus on those theories whose development I was closely involved with: the selfcompletion theory , the mindset theory of action phases Gollwitzer, 1990), and the theory of if-then planning (Gollwitzer, 1999(Gollwitzer, , 2014. So the focus is not on discussing the many different goal theories that have been developed and tested in the psychology of motivation by addressing the consequences of setting, striving for, and attaining goals of a different kind, or the various self-regulation strategies that have been suggested to help people commit to, pursue, and attain these goals. Rather, I'll try to demonstrate convincingly that the goal concept is a powerful tool when it comes to creating theories that facilitate the understanding of phenomena that are at the center stage in the science of motivation.